Wobble is the relaxation of base-pairing rules in tRNA
. This helps fill in the 16 amino acid codons
is missing (compaired to mRNA
which has 61 amino acids
In order to understand wobble, one must first know this:
DNA his comprised of a double-helix. Each strand of DNA is made up of nitrogenous bases (either A for adenine, T for thymine, G for guanine, and C for cytosine). From one strand of the double-helix (the template strand), mRNA is transcribed, echoing the nitrogenous bases (besides replacing 'T' with 'U'). mRNA then travels out of the nucleous and into the cytosol, where it is at some point read by tRNA. tRNA is a funny fella. It connects to the mRNA with aid from ribosomes.
Time for an example:
This first are two fictional strands of DNA, wound into a double helix:
mRNA would pick one of those strands (the top one for example) to use as the template strand, and create this:
(notice that 'T' does not exist in mRNA, and is replaced by 'U')
End of example
Also, let it be known that mRNA is read in threes. This means that every three nitrogenous bases forms a new amino acid codon (UCG, UCA, and CGG happen to be the first amino acid codons in our facticious strand). tRNA has three nitrogenous bases that are in tRNA's 'anticodon' region, and thus echo an amino acid's structure in mRNA.
Again, time for example:
For example, our first amino acid, 'UCG' in mRNA, would be complemented by an anticodon from tRNA with the sequence of 'AGC', like so:
The first line is the tRNA anticodon, which affixes within a ribosome with the mRNA strand.
End of example
The wobble comes in when it was relized that a strand of tRNA only had about 45 amino acid codons, while there are 61 possible amino acid codons that mRNA can handle. Thus, scientists found that the nitrogenous bases tended to 'wobble' across the anticodon, thus actually allowing for more combinations of amino acid codons in the same tRNA.
The concept may seem scary or complex, but it really isn't. Go hit me up on the Chatterbox if you just don't get it :)